One of the things I learned from my FASERIP expedition into magic was that spells didn't really change based of the Rank, your chances of success were based on Rank.
For example, Alteration -- Appearance would let you change your face and appearance to anyone else. Anything beyond changing to someone with a similar build and face required a roll.
So if I had this spell at Feeble rank, the weakest rank, I could change at will to anyone with a similar build and face. I would be very unlikely to do more than that, because of the required roll.
For Red Concordant, I though about a different form of magic as a player option. All spells have a free relatively weak effect, but anything beyond that would require an level test (roll d12 under, but not equal to your character level). Spell descriptions would be per my Alteration -- Appearnce example.
I like it because it introduced a new kind of simple to magic. In other words, spell description are still terse, but greater effects work, or they don't. More powerful spellcasters will have better chances of success. At level 13, success becomes automatic.
This would also simplify spell slots. Essentially, a spell caster can cast X spells per day. No table, no varying spell levels, just a number that can be tracked by tick marks.
I'm beginning to feel like I will need to make a book of magic after I finish the RC project. 🙂